This section provides background information related to the present disclosure which is not necessarily prior art.
Technical Field
The invention relates to a high-pressure plate heat exchanger having a plate packet which is of polygonal design and is arranged in a pressure chamber provided by a housing, wherein the housing has convexly curved flange covers.
Discussion
The high-pressure plate heat exchanger has a plate packet. The plate packet has, for example, first and second channels through which media can flow and which are arranged in cross flow or, in the event of multi-way capability, in cross counterflow. The first channel, which is provided for the first medium, is formed in a tubular manner between individual plates which are connected to one another to form a plate pair, and the second channel, which is provided for the second medium, is formed in a wavy manner between plate pairs which are connected to one another to form a plate stack.
A plate packet of the previously described type is known from DE 43 43 399 A1. A plate heat exchanger is disclosed here having channels through which the flow passes in cross flow and which, for the one medium, are formed in a wavy manner between individual plates which are in each case connected to form a plate pair and, for the other medium, are formed in a tubular manner between the plate pairs which are joined together to form a plate stack. In order to form the channels, the individual plates are equipped here with a plurality of parallel rows of cams or embossed supporting structures which are oriented in the flow direction of the one medium and are formed offset with respect to one another from row to row in the longitudinal direction. Furthermore, other embodiments of plate packets are also known.
The construction known from DE 43 43 399 A1 is not suitable for high-pressure applications, i.e. for media pressures of greater than 25 bar. This is not suitable in particular since said construction does not have sufficient mechanical stability for higher pressures and therefore may be deformed beyond the permissible extent at higher pressures.
In order to implement high-pressure use, plate heat exchangers in which a plate packet is arranged in a pressure chamber provided by a housing, which housing is closed on the end sides by convexly curved flange covers, are therefore known, for example from U.S. Pat. No. 5,755,280.
However, these plate heat exchangers are not suitable for all applications. The construction according to U.S. Pat. No. 5,755,280 thus has the requirement that the plate packets arranged closest to the flange covers have to be connected with the intermediate arrangement of an elongate connecting piece to a circular opening in the flange cover. This is required in order to be able to connect the plate packet of polygonal design in a fluid-tight manner to the connection, which is of circular design, in the opening of the flange cover.
It is disadvantageous in this connection that said connecting piece significantly extends the plate heat exchanger, and therefore the constructional shape of the plate heat exchanger cannot fall below a certain minimum size from the outset. In addition, the free corners of the rectangular plate packet are not suitable for high differential pressures.
Added to this is the fact that the connecting pieces have to be connected in a precisely fitting manner both to the plate packet and to the flange cover, which entails the risk of leakages or predetermined breaking points arising even during the assembly of the plate heat exchanger.